A sealing device that seals a sealed object by sucking out gas from or supplying gas to the inside of the sealed object is known from Patent Document 1. According to Patent Document 1, a nozzle is inserted into the sealed object from its opening, and the air inside the object is sucked out, or gas is supplied to the inside, with the opening and the nozzle being held between a pair of holders (at a first holding position). After that, the nozzle is pulled out from the opening, and, with the opening further being held between the holders (at a second holding position), the object is heat-sealed. This holding operation with the holders is performed by driving one or two air cylinders.
A sealing device that uses a linear solenoid is known from Patent Document 2. Patent Document 2 describes holding a sealed object with a pressure element of a pressure lever that moves up and down with a movement of a linear solenoid and a heating element.